Breechblock operating mechanism



h 8, 0- w. SUMMERBELL 2,216,860

BHEECHBLOCK QPERATING MECHANISM Filed May 22, 1959 lnvarltnv' William 5mm #13211 By *i/y x At t EIH'FLEYS Patented Oct. 8, 1940 UNITE BREECHBLOCK OPERATING MECHANISM successors in office Application May 22, 1939, Serial No. 274,988

1 Claim.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a breechblock operating mechanism.

The purpose of the invention is to provide a breech mechanism for rapid firing small caliber cannon especially adapted for firing on moving targets.

Automatic and semi-automatic breechblock operating mechanisms have been provided for small cannon for the purpose of permitting the gun crew to obtain a rapid rate of fire but the construction and installation of such mechanisms involves considerable expenditure of time and money. With a view to facilitating production in an emergency it is proposed in this invention to arrange and mount a manually operable breechblock operating mechanism so that a gun crew can manipulate it rapidly and without danger.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawing in which:

Fig. 1 is a view in right side elevation of the breech end of a gun equipped with the improved block operating mechanism.

Fig. 2 is a fragmentary View in rear elevation with part of the handle broken away.

Referring to the drawing by characters of reference there is shown a breech ring 5 of a recoil gun having a vertical opening for a sliding drop breechblock 6.

The mechanism for lowering and raising the breechblock comprises a lever l which is fixed on a splined shaft 8 journaled in spaced depending lugs 9-43 on the breech ring. The upper or free end of the lever 1 is formed with laterally projecting studs Ill-J riding in an inclined slot II in the breechblock. As the lever 1 moves rearwardly and downwardly the breechblock will be lowered and during its forward or upward movement the breechblock will be raised to closed position.

The splined shaft 8 projects from the right lug 9 of the breech ring and receives the hub of a handle l2 which is fixed in any convenient manner, as by welding and includes a bearing 13 inserted in the lug 9. The handle extends outwardly with respect to the side of the breech ring so that its upper hand-engaging portion I4 is at a sufficient distance from the breech ring to enable it to be grasped without danger to the operator when the gun is moving in counterrecoil.

The hand-engaging portion 14 is formed with a slot l5 opening in the forward face and receives a latch l6 which is mounted on a pivot pin ll,

The latch is normally maintained in extruded position by means of a spring 18, the limit of its movement being determined by the portion l4 adjacent the pivot pin. The latch is formed with a notch to provide a hook I9.

A pair of spaced parallel rails 2lI-20 are fixed to the side of the breech ring in an inclined position which is substantially tangent to an are drawn from the shaft 8 as: a center. A latch plate 2| inserted between the rails 20 has a laterally extending foot 22 at its forward end. The upper rear edge of the foot is cut away to provide a cam surface 23 which as best seen in Fig. 2 is inclined with respect to the breech ring so as to be normal to the inclined handle.

In Fig. 1 the breechblock is in the closed position and the handle is inclined forwardly with the hook IQ of the latch engaging the foot 22 of the latch plate. When the gun is fired it moves in recoil and then in counterrecoil. During the final portion of the counterrecoil stroke the operator interposes his hand, palm rearwardly, in the path of the handle, so that the forwardly moving handle will engage a resistance to disengage the latch and then cause the handle to be rotated to lower the breechblock. The block is thereby opened and the empty cartridge case is extracted by the time the gun arrives in battery. The gun loader immediately throws a new round into the chamber of the gun and the block operator has merely to close his fingers on the handle and move it forwardly to raise the breechblock to closed position. During the forward movement of the handle the hook l9 rides up the cam surface 23 and is then forced by the spring l8 to engage the foot 22 and securely lock the breechblock in the closed position.

The operation of opening the block while the gun is moving into battery is performed safely and without effort and results in the attainment of a rapid rate of fire.

I claim:

In a gun, a breech ring, a vertically sliding breechblock in the breech ring, a shaft journaled in the breech ring, a lever fixed on the shaft and slidably engaging a cam groove in the breechblock, a handle fixed on the shaft, said handle being inclined with respect to the adjacent side of the breech ring to space its outer end from the breech ring, a latch pivotally mounted in the handle and normally extruded from the front side of the handle, a hook on the latch, a latch plate fixed to the breech ring in an inclined position tangent to an arc drawn from the shaft as a center, and a laterally projecting foot on the latch plate having a cam surface disposed in the path of the hook on the latch.

WILLIAM SUMIMERBEHL. 

